1. Technical Field
Novel photoresist monomers, polymers thereof and photoresist compositions containing the same are disclosed. In particular, photoresist polymers suitable for a photolithography process using DUV (deep ultraviolet) light source such as VUV (157 nm) in fabricating a minute circuit for a highly integrated semiconductor device, photoresist compositions containing the same, and preparation process therefor are disclosed.
2. Description of the Related Art
A photoresist for an ArF and VUV (vacuum ultraviolet) should have low absorbency at 193 nm and 157 nm wavelengths, excellent etching resistance and adhesiveness on a substrate, and should be easily developable in a commercially available developing solution, such as aqueous tetramethylammonium hydroxide (TMAH) solution of 2.38 wt % or 2.6 wt %.
Much research has been conducted on resins having a high transparency at 248 nm and 193 nm wavelengths, and etching resistance similar to Novolac resins. However, most of the studied resists are not suitable for VUV due to their high absorbency at 157 nm wavelength. Other research on photoresists containing fluorine and silicon has been conducted to solve the above problem. However, most polyethylene or polyacrylate polymers containing fluorine have weak etching resistance, low solubility in an aqueous TMAH solutions and poor adhesiveness to the silicon wafer. In addition, these photoresists are difficult to mass-produce and are expensive.
Photoresist monomers containing a benzylcarboxylate substituted with fluorine are disclosed.
Photoresist polymers containing the above photoresist monomers are also disclosed.
Photoresist compositions containing the photoresist polymers described above and processes for forming a photoresist pattern are also disclosed.
Semiconductor elements produced using the photoresist compositions described above are also disclosed.